Method of and apparatus for reducing the velocity of fluids



July 21, 1936. A. G. MCKEE 2,048,613

METHOD OF AND APPARATUS FOR REDUCING THE VELOCITY OF FLUIDS.

' Filed oct. 1o, 1952 Patented July 21, 1936' UNITED STATES METHOD OF AND APPARATUS FOR REDUC- VlN'G THE VELOCITY 0F FLUIDS A Arthur G. VMcKee, Cleveland, Ohio Application October 10, v1932, Serial No. 637,094

5 Claims. (o1. 18s-107) This invention relates to the art of handling Afluids. It is primarily concerned with methods Vand means for reducing the velocity Aof a uid fiowing rapidly in an enclosure, such as a, pipe or the like. In certain of its aspects the invention relates to the reduction in velocity of a liquid or a ges-and in other aspects it relates to the reduction in velocity of a gas and a Vseparation therefrom of solids.

Among the practical uses of the present inventionare the following: Liquid; Vsuch as water, which is fiowing rapidly in a pipe or similar passage may be greatlyreduced in velocity without excessive disturbance. The velocity of gas flowing at a high speed in a pipe may be -rapidly and smoothly reduced. For example, the exhaust 'gasesfrom an engine may be rapidly reduced in velocity and'at thesame time the noiseofthe eX- plosion may -be greatly reduced.Y Rapidly moving gases, containing solids, may be effectively 'hanfdied so `as `greatly to decrease the velocity of the gases `and at the same time to separate the solids therefrom. This latter application of the invention will be specifically described hereinafter.

' In the drawing accompanying and forming a part of this speciiication- Figure 1 is a vertical Asectional view-of one form lof Vapparatus embodying the present invention and adapted for 'handling'blast furnace gases and `separating solids therefrom.

'Figure 2 lis a horizontal sectional View taken on line 2-2 vof Figure 1.

'Figure 3 is a modied form of apparatus for use `in the handling of gases or liquids.

Figure 4 is a perspective view of thestream line diffusing core member shown inFigures 1, 2 and the creation of eddy currents which effectively prevent a smooth fiow ofthe uid during retardation of its velocity. In case of gases carrying solids, such .eddy currents prevent the separation of thevsolids therefrom to the desired extent, and in `tmany instancesresult in apicking up of previously .separated solids. 4Thepresent invention avoids these disadvantages and 'makes it possible not onlysmoothly and rapidly to reduce the vvelocity :the flowing fiuid without creating eddy currents i sage may be rapidly and smoothly reduced by the Vsteps of changing a more vor less cylindrical stream of fluid into a hollow cylindrical stream abruptly but without the creation of Aeddy currents exceed- -ingV a permissible maximum in magnitude, and

' thereafter gradually and smoothly decreasing the space within the stream, preferably accompanied" by a gradual and smooth expansion of the outer *diameter of the stream, and if desired, with a final conversion of the hollow tubular stream into fone of Ysolid cylindrical form. Obviously, various types of apparatus may be employed for the fore- 'going purposes, but generally Yconsidered they include a cylindrical pipe or passage for the fluid, amore or less stream line core member axially aligned with'the pipe, with-the end thereof adjacent the pipe being rather blunt but not sufli- Vciently blunt to produce eddy currents of greater than the permissible magnitude, with the core decreasing in cross sectional area toward the end remote from the pipe toresult in a smooth flow -of huid therepast without creation Aof undesired 30 ,eddy'currents, and a continuation of the pipe whichl surrounds the core and preferably increases more or less regularly in diameterso that Anear the end of the core the diameter of the continuation is much` greater than the diameter of the pipe.

Referring to the drawing, wherein one embodiment of my invention is disclosed, the shell I is provided with a hopper-shaped bottom 2 to 'collect solids which may be removed-through 40 manholes 3 or 4. The shell I isv provided with an outlet. A gas inlet pipe or conduit 6 serves to lead downwardly into the shell l a substantially cylindrical stream of gas, suchv as blast furnace gas containingsolids, and vmoving at high velocity. 'I'he velocity of such 'gas may be more than 3000 feet per minute. At the lower end of the pipe `6 a core `1 is disposed in axial alignment therewith. This core has a pointed but rather blunt-nosed end adjacent to the end of pipe 6, increases in diameter from the nose for a `port-ion of its length and then decreases in diameter to the pointed tail end 9. 'I'he core 1 Yis symmetrical about its longitudinal axis, and its outer surfaces are smooth and stream lined `55 point along its length. e

A continuation of inlet pipe 6 is designated byV the numeral H).V VVThis continuation gradually and smoothly increases in diameter from approx- Y Vimately .the nose Yof the core I to approximately the tail of the latter.

tion I Vof the pipe 6 is approximately frustoconical in form and terminates nearthe Vtail 9 of the'core. VThroughout its length it isV spaced apart from the Walls of the shell I, so that gases passing therethrough may reverse their direction of flow and pass upwardly between the enlarged continuation l0f andthe shell LandVV finally escape'from the shell through the outlet 5. The

lower end of the continuation VIIJ is spaced a sufficient distance above the hopperA bottom l2 s o that the ,gases which pass around the lowerend of the continuation l0 will have plenty of space '.t'ollow above solids collected in theohopper 2 of Vshell, l. er

The operation ofthe apparatus `just described is substantially as follows: o Y j Y,

ABlast Vfurnace gas carrying solid particles and Vmoving VVat a velocity-of perhapsBOOO feet per.

minute ormore, flows in a substantially cylindrical stream downward through a pipe 6. When this streamV strikes the blunt nose 8 of the core 1, Yit is changed into a hollow tubular stream abruptly, yet withsuilicient smoothness to prevent Vthe formation of Vharmful eddycurrents. The

Y ual decreasein the size of the interior or core gas continues on, the core 'Lpermitting the gas gradually and smoothly to expand inwardly, thus gradually closing up the interior'space, and due to the diverging Walls'of the continuation I0 the gas is permitted simultaneously to expand outwardly. YThe abrupt change from asolid. cylinspace, together with the enlargement in the outside diameter ofjthe stream, results in Va slower reduction of velocity,v the total result,V Vas far as gas velocityisV concerned,- being that the gas vis after it has passed the nose'endV of the core 1, so that the velocity of the. gas is reducedY several thousand feet 'per minute in traveling through the extension l0, and Vthis treduction is notacstantially the same diameter as the inside of the cQmpanied by-creation of eddycurrentsotundesired magnitude. Y

Since the nose portion of thecore I isV of s ubpipe, substantially all the solids carried by the gas will strike against the sloping surface ofA the core Vand 'glance off, some of them possibly Vstriking theinside of'the continuationlbut none fof-.the solids having theiryelocity materially reduced thereby. Thus they continue YVtheir f' forward Vmovement ata high rate of speed, outdis- Y tom of the shelll, wherethey'collect. Inthis -tancing the gases kand continuing on to the botmanner the velocity of the gas may be rapidly and smoothly reduced,V while the velocity of the solids isj not greatlyY reduced and with` the result that the solids will not; be carried upwardly v by the' gases when the latter reverse their direction-atethe lower end VVof the' continuation I ll. l

" The absence of eddy currents of undesired magnitude at points below the endrof theY continua- Vtion l0, results inthe solids remaining quietly This enlarged end por-V in the hopper portion 2 of the shell I, after having been projected thereto. .Y In Figure 3 a modiiied'form of the present invention'is shown, .which modication may -be employed for use with gases or liquidswhere the primary object is merely to decrease the velocity. A cylindrical stream of fluid owing through pipe l lV encounters a core I2, is abruptly changed thereby into a hollow. tubular stream, which stream is again changed into a cylindrical stream of larger cross vsectional area fafter the fluid has passed the core 12'.V VSince no eddy currents of more than the permissible maximumV are created,'th e velocity is smoothly decreased without, any Vof the results ordinarily .attendant on 15 the pressure of eddy currentsiofgreat magnitude.V Y

f In Figure 5 the change in velocity of a gas has been plotted against the change .inV cross sectional area of the stream of fluid when using a device of the character shown in Figure 1. f It will benoted that the initial velocityV of ,thegas'f at the endv of pipe 6 is more than 3500'feetper minute, and that this velocity-has beenreduced. n to less than 1000 feet per minute within a .dis-1 tance of Vten feet, afteruwhichV the velocityvde- Y creases slowly. VAt Ythe same Ytime Qthedarea Vof the streamhas increased from thatof `.theV pipe 6, which .is something underO square feet'to an area of about 150 square feet, at adistance `of ten f eetfrom theV end of pipe 6, and to an area'V Yof about 400 square Yfeet at thejend ofY continuation l0. n j f j-A In connection with the curves plotted in Figure /5 lit will be notedthat Vthe curves indicate a1rapid but smooth reduction of velocity at first, which reduction proceeds at 'a gradually decreasingraterto theend of the continuation I0 and whichreduction is'caused by a correspond- Y 4 ing gradual increase of areaV as Vshow npin the curves. Y j 40 Having thus described my `invention. what,I desire to,l secure by Letters Patent isYY di ei ned .;lnY

what is claimed.V n I claim;

1. Apparatus combination,a.housing forming acleaning chamber, an inletpipe leading to said cleaning chlamber and having a Vfrusto-conical enlargement-lying within saidv cleaning chamber, an outletpipe, andrmeans for diffusing the gaS'OWQintothe' frusto-concal part of said -inle't pipe, saidmeans comprlsingja diffusing corejrelativelyfblunt atY f Vthe forward end and having kan elongatedvtapering tail; the -cross sectional' area of.the space between saidcore and said Venlargement increasingon successive planes normal to .thelongitudinal axisofthe core fromrthe 'bluntend ofgsaid core to the tail end thereof. V2. VIn apparatusof the type described,the V orn- Vbination of a housinghavingV an inlet-conduit leading thereinto, a frusto-conical 'enlargement disposed at the. endnf `Seid inlet: vendait`V within said housing and jadaptedto Vform a velocity reducing chamber, and a stream linedrcore memspaced therefrom with one en d adjacent the junc-l y .tion ofsaid inlet conduit and said'enlargement, thecross sectional area ofjthe space between :said Vstream lined core memberand said enlargement Y( increasing-on `successive planes normal'to rthe longitudinal axis of thecore from the Yend offsald core adjacent the junction of :said inlet conduit `and said enlargement to the opposite end thereof. J 3. Apparatus for reducing thelvelocity off a 1 moving streamer numY including azconduithav-.J

for Ycleaning 'gas V45 bei" Vsuspended fwithin; said.V enlargement f and v ing an enlarged velocity reducing portion and a stream lined body suspended in said velocity reducing portion, said stream lined body having a relatively blunt head portion and an elongated tapering tailA portion and being disposed in said enlarged' velocity reducing portion of the conduit with its head end upstream ofthe moving stream of fluid, the cross sectional area of the space between said stream lined body and said enlarged portion ofvsaid conduit increasing on successive planes normal to the longitudinal axis of said stream lined body from the blunt head portion oi said body to the tail portion thereof.

4. The method of reducing the velocity of a gas which includes the steps of flowing the gas in a stream, abruptly and smoothly changing the gas from said stream into an annular or hollow stream of increasing cross-sectional area, causing the total cross-sectional area of the hollow stream of gas; and the center of said hollow stream of gas to increase and the cross-sectional area of the hollow center alone also to increase, and then causing the total cross-sectional area of the annular stream of gas and the hollow center thereof to continue to increase while the crosssectional area of the hollow center of the annular stream is gradually reduced in a sharply dened path without the creation of substantial eddy currents until the gas forms a solid stream of greater cross-sectional area than said first named stream. Y

5. The method of reducing the velocity of a stream of gas which consists in causing a column or current of gas to change into an annular or hollow current of gas, the outside and inside cross-sectional dimensions of said hollow current of gas both increasing for a predetermined distance along the path of gas travel, and then causing said hollow current to gradually and smoothly change to a solid current without the creation of substantial eddy currents by continuing to cause the outside Ydimension to increase while gradually decreasing the inside dimension of the hollow stream whereby the inside and outside of said hollow stream both follow sharply defined paths and the stream changes into a column of greater area and lower velocity than the original current.

ARTHUR G. MCKEE. 

